Roush, 68, and an assistant were flying into town for the Experimental Aircraft Association's AirVenture show when his plane left the runway at Wittman Regional Airport, the Milwaukee Journal-Sentinel reported Wednesday.
AirVenture spokesman Dick Knapinski said after departing the runway the Beechcraft Premier came back down and then skidded to a stop.
Photos taken at the time of the crash Tuesday evening show Roush being helped from the damaged aircraft with apparent facial injuries, the Journal-Sentinel said.
A statement from the Experimental Aircraft Association said Roush was hospitalized in serious but stable condition.
His assistant Brenda Strickland was hospitalized with injuries described as non-life-threatening.
An aviation buff, Roush owns several planes.
He miraculously survived a crash in April 2002 with a serious head injury, a shattered leg and broken ribs.